Polyamine synthesis pathway

The **polyamine synthesis pathway** refers to the suite of enzymatic reactions responsible for generating polyamines such as putrescine, spermidine, and spermine from precursor amino acids—primarily ornithine and methionine—in both animal and plant cells[1][4][6]. The pathway’s core enzymatic steps include ornithine decarboxylation (catalyzed by ornithine decarboxylase, ODC), successive aminopropyl group transfers, and subsequent regulation at multiple steps, including synthesis, transport, and catabolism[3][6]. Polyamines bind nucleic acids and proteins, modulating chromatin structure, translation, cell cycle progression, apoptosis, and DNA repair, and acting as regulators of ion channels and embryogenesis[1][4][6]. The pathway is highly active in rapidly proliferating cells and is often dysregulated in cancers—hence, targeted by anti-tumor agents such as DFMO (an ODC inhibitor) and polyamine transport inhibitors like AMXT 1501[2][5][8]. Pathway inhibition reduces tumor cell growth but may trigger compensatory uptake; combined blockade of synthesis and transport is a proposed therapeutic strategy[8]. Notably, the term “polyamine synthesis pathway” refers to an interconnected set of enzymes and metabolic regulators, not a single protein or canonical drug target; thus, molecular targeting strategies often focus specifically on ODC, polyamine transporters, or other defined components[1][2][8].

Other names

Polyamine biosynthesis pathwayPolyamine metabolic pathway

Inhibition of ornithine decarboxylase (ODC) to block polyamine synthesis; Inhibition of polyamine transport proteins to prevent cellular uptake; Polyamine analogues acting as competitive inhibitors or inducing cytotoxicity